1. Field Of The Invention
The present invention relates to oil well drill pipe cleaning and more particularly relates to an improved method and apparatus for the cleaning of oil well drill, pipe threads wherein an improved solvent based cleaning and filtration system features a continuous closed loop flow system that continuously filters hydrocarbons, scale, rust and the like from the solvent, as generated during the mechanical cleaning of the drill pipe threads.
2. General Background
In the drilling of oil wells, a plurality of lengths of drill pipe are connected end to end and slowly extended down into the earth forming what is called in the industry a drill string. Drill strings can be thousands of feet in length and typically are lengths of cylindrical pipe having an open ended bore which is also cylindrical. At the ends of these lengths of pipe there are provided threads which include external threads on one joint and a corresponding connecting portion on the next joint which includes internal threads. These threaded end portions of drill pipe are often referred to as "pin" and "box" end portions.
The cleaning of drill pipe must be done on a regular basis because the environment of oil well drilling subjects the drill pipe to accumulations of drilling mud, soil and other formation material, rust, scale and the like.
One prior art method of cleaning drill pipe is through the use of an abrasive rotary wire brush machine which is powered by a rotary device such as an air powered drill. A shroud has been used to encapsulate the end of the drill pipe so that the removed scale, rust, dirt, drilling mud, hydrocarbons and the like are captured by the shroud and so that the material that is removed from the drill pipe does not pose a threat to the operator of the power tool which is used to remove the drill pipe. The shroud simply catches scale, rust and the like and prevents that material from flying through the air and hitting the operator in the eyes or face.
The use of a solvent increases the effectiveness of the mechanical action of the wire brush, but generates significant particulate matter including rust, scale, tar, drilling mud and the like which renders the solvent dirty and less effective as well as a pollution problem requiring disposal.